Forming protective packaging for various articles of different sizes and shapes is a common problem in the packaging industry. Articles which are fragile in nature as well as those which are heavy tend to cause the most concern in packaging applications. In many circumstances, such articles are either desirably or necessarily packaged within generally square or rectangular packaging cartons for handling and shipment. Where the size and shape of the article to be packaged varies from such rectangular or square shaped containers, a typical solution is to include some sort of cushioning material to fill up the otherwise empty space created by the difference in shape and size of the article and that of the container.
Prior packaging methods which exist include the use of loose, friable material, sheets of cushioning material, and foam-in-place packing. Several patent references disclose foam packaging methods. U.S. Pat. No. 3,222,843 to Schneider discloses a gusseted bag filled with an expandable cushioning material. U.S. Pat. No. 3,190,442 to Gauss discloses the placement of a cushioning device in the storage container as well as an expandable material and a chemical formula for foam. U.S. Pat. No. 3,485,347 to McGill et al. discloses foam cushioning packages formed by adding a foamable material through flexible tubing folded to fit in the shipment container. While these patents provide several alternatives in size or shape of bags used for package cushioning, disadvantages remain in all three. In particular, no method for automatically concurrently forming and filling the bags is provided. Also, none of these patents address the issue of manufacturing the same style of bag in various shapes and sizes.
U.S. Pat. No. 3,851,814 to Stage discusses a method of forming a gusseted plastic bag from two webs of material in a face-to-face configuration. Stage, however, provides for the formation of bags for somewhat sophisticated applications (i.e. sanitary packing of medical devices) from two webs of different material. Nevertheless, certain disadvantages remain. In particular, Stage discloses no method for filling bags with foam, or any other material during formation of the bag.
U.S. Pat. No. 4,318,506 to Hirsch and U.S. Pat. No. 3,659,775 to Truman, both disclose gusseted bags. Hirsch provides a contaminant free bag formed by converging two webs potentially having different widths. Disadvantages remain, however, in that Hirsch does not provide a means for concurrently forming and filling the bag. Also, in the event expandable foam material were inserted into the bag, resulting expansion would likely cause the adhesive top seal of the bag to break loose resulting in spillage of the expandable foam material once the packaging cushion is in place. Although Truman does disclose a gusseted bag, the disclosed technique is disadvantageous in that it uses a single web rather than two converging face-to-face webs to form the bag, thus resulting in a need for specialized machinery.
A greatly improved approach to the manufacture of foam-in-place packing is disclosed in the above-referenced U.S. Pat. No. 4,800,709 and pending application Ser. No. 235,013. Both of these disclose an apparatus and method for forming foam cushions for packaging purposes whereby the foam cushions are formed by converging two sheets of plastic-like material in a face-to-face configuration and heat sealing the edges of the respective face-to-face sheets together to form a bag in which a foamable composition is enclosed.
One or more of the resulting bags may be placed in a box along with an article to be shipped. Shortly after the box is sealed shut, the foamable composition expands encircling the article to form an instant custom package. As further discussed in these disclosures, the method produces a cushion that has a ventilation opening in at least one side edge. The opening allows gases generated by the foamable composition to exit the bag so that the resulting cushion is almost entirely filled with foam rather than foam and air. The apparatus and method permit continuous manufacture of foamable cushioning packages and have greatly facilitated the automatic formation of custom packages while preventing spillage of the foam cushioning material onto articles as they are being packed.
One area for improvement in the method, however, is that packing cartons for shipping articles tend to vary widely in size and shape depending upon the size and shape of the articles to be shipped. As a result, various size foam-in-place packing are advantageous, desireable or necessary. Typically, however, the equipment described in the referenced patent and pending application is obtained and used in one particular size. The apparatus does permit the length of the cushions to be varied during continuous production, but changing the width of material used requires either an adjustment or a different size apparatus. Therefore when packages of relatively large variance in size are required, wider cushions must be manufactured by a different sized machine.